Patent · US Expired

Light pattern generator

US4779176A · kind A · utility

82Cited by
6References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 16, 1986
Grant dateOct 18, 1988
Priority date
Expiry dateJul 16, 2006

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF21W2131/406
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A light pattern generator is utilized to produce an image which is projected onto a stage or screen. The image is derived from a beam of light. The light pattern generator comprises a heat resistant glass plate having a reflective layer deposited on one surface thereof. A nonreflective layer is deposited on the surface of the reflective layer. Both of the layers are etched to produce an opening extending through the layers wherein the opening has the shape of the desired image. The beam of light is directed through the transparent plate and the portions not passed through the opening are reflected by the mirror surface of the reflective layer. This prevents the buildup of heat within the light pattern generator. Any extraneous light which is received at the nonreflective layer is absorbed to prevent the escape of unwanted light and its projection to the stage.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.